Veteran political strategist and informal adviser for GOP frontrunner Donald Trump Roger Stone warns on Breitbart News Daily that the loss in Wisconsin should be a “wakeup call” for the Trump campaign, which he says should invest in campaign infrastructure to sew up the party’s nomination.

“It’s an early wakeup call, as it were, for the Trump campaign,” Stone, who predicted earlier that Trump would lose Wisconsin, tells Stephen K. Bannon.

Trump’s campaign has been fueled, from the beginning, with these hot button issues and an extraordinary communications-based strategy, where you utilize these huge rallies, the incredible media coverage they have generated, plus the high-profile debates, plus — give Trump credit — any interview he could do, as many interviews as he could do to reach as many voters he can reach. And that has worked. Up until now.

“The campaign has no infrastructure in the states,” he continued.

The woman who ran Wisconsin for Trump previously ran Oklahoma for Trump. Trump lost. Prior to that, she had never run any political campaign, so there was no depth of experience. This is something I see again and again, particularly at the ground roots level. Now, I salute these people for their enthusiasm, but this is a science. This is not something we guess about. And now you move to a serious of states like Colorado, Wyoming, and Arizona [which] should be watched very carefully. And those become hand-to-hand combat at state conventions or state committee meetings, where once again the Trump people have built no infrastructure.

Stone added that Trump’s current predicament reminds him of Ronald Reagan’s failed 1976 run. “The Trump people are playing catch-up ball. They have to still worry about New Jersey, New York, Delaware, and Pennsylvania, some big states going forward which are winner-take-most,” he said. “But we also have to wonder, what is the psychological impact of Trump’s support in those states now he has lost a stand-alone primary and lost it by double digits.” But, he noted, Trump still leads in upcoming primary states substantially.